Sandler, whose Happy Madison shingle is also a producer on the pic, will voice a capuchin monkey. Cher’s voicing a giraffe, Favreau a bear, Stallone a lion and Apatow an elephant.

Jim Breuer, Faizon Love and Bas Rutten round out the voice cast.

James is also producing with Todd Garner (“The Sorcerer’s Apprentice”) and Happy Madison. Jeff Sussman and Jennifer Eatz exec produce.

Pic centers on zoo animals trying to teach the keeper their methods of dating and mating to help him win back the woman of his dreams. Frank Coraci is directing from a screenplay by Jay Scherick and David Ronn, James, Rock Reuben and Nick Bakay.

Shooting’s set to start in late summer for an Oct. 8, 2010, release. MGM won a bidding war last year for the “Zookeeper” spec, paying $2 million against $3 million, while the studio was ramping up a slate of homegrown projects.

Happy Madison’s shooting “Grown Ups” with Sandler, James and Chris Rock for Columbia.